In my software engineering career I have taken 200+ coding interviews.

In this article, sharing top 10 most common blunders interviewees make in the interviews and tips on fixing them.

TL;DR

• Not understanding the problem
• Not asking questions
• Not planning before coding
• Not thinking out loud
• Not using hints
• Not giving brute-force solution
• Not optimizing the solution
• Not speaking while coding
• Not knowing Big O notation
• Not testing the solution

❌ Not understanding the problem

Fix:

✅ Re-read the question until you understand constraints and edge cases.

✅ Re-phrase question in your own words and verify understanding with the interviewer.

❌ Not asking questions

Fix:

✅ Clarify any detail about the problem you find ambiguous.

✅ Ask for problem constraints. Range of values, size of input, etc.

✅ Ask the interviewer if they prefer time or space optimized solution.

❌ Not planning before coding

Fix:

✅ Determine starting and ending points for solving the problem.

✅ Develop a high level algorithm before refining details.

❌ Not thinking out loud

Fix:

✅ Discuss solution approach with the interviewer.

✅ Walk them through your implementation by dry running code.

❌ Not using hints

Fix:

✅ Acknowledge the hint and how does it help.

✅ Expand on hint and see where else can it improve the solution.

❌ Not giving brute-force solution

Fix:

✅ Start by sharing simplest brute force solution.

✅ Explain why the approach is sub-optimal.

❌ Not optimizing the solution

Fix:

✅ Go through the solution step by step and identify the inefficiencies.

✅ Resolve inefficiencies by using right data structure or algorithm for the task.

❌ Not speaking while coding

Fix:

✅ Keep explaining to the interviewer what you are coding.

✅ Don’t speak code verbatim, also explain why you made a decision.

❌ Not knowing Big O notation

Fix:

✅ Know time and space complexity of classic algorithms.

✅ Practice calculating complexity of your code.

❌ Not testing the solution

Fix:

✅ Dry run the code with sample inputs and edge cases.

✅ If code doesn’t work, show that you understand why is that so.

Wrapping up 📝

Hope you will avoid these blunders in your next coding interview.

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Also, share ONE interview mistake that you never want to repeat in comments. 👇